DE-OS 24 48 398 and DE-OS 28 00 844 disclose measuring devices with which elastic mats including capacitor areas are provided to enable measurements of the normal forces acting on the mats. However, an areal distribution of the compressive forces cannot be resolved by these devices.
A measuring arrangement for the areal distribution of compressive forces is known from DE-OS 25 29 475 and this will be especially referred to here. The mat according to the invention can be operated with evaluating electronics shown in that publication and which can be used with the present invention. Accordingly, the electronics for evaluation will not be described in greater detail herein.
Starting from DE-OS 25 29 475 mentioned above, a device of the kind recited initially has become known from DE-PS 30 25 362. That device reveals a special concept of the conductor paths, a concept chosen because simple conductor paths fixed on an elastically deformable area-type dielectric allegedly involve poor electrical characteristics (non-linearity, hysteresis), as well as poor mechanical properties (signs of relaxation, fatigue of material, limited flexibility). Furthermore, such publication reveals that the devices are useful exclusively on a hard, planar background. It is also pointed out in that publication that such simple arrangements bring mechanical tight coupling with adjacent capacitors. It is suggested in the publication that those disadvantages be avoided by applying special grid conductor paths in a special manner. Yet, that arrangement is extremely complicated and especially unsuitable for use, for example, when a measuring arrangement is to be made which is to be worn in a shoe, as regards the flexibility. Problems relating to flexibility also occur when the measuring surface is placed on a motor vehicle seat (to measure the sitting behavior of test persons). Moreover, mass production of such a measuring mat is almost impossible because of the great expenditure involved.
A measuring arrangement of the kind mentioned initially is known also from DE-OS 34 11 528, and it likewise is aimed at improving the electrical and mechanical properties. In that publication too, it is stated that strips of metalized plastic sheeting or film were not suitable as conductor paths. It is suggested in the publicaton to sever the individual measuring areas obtained at the points of intersection of the conductor paths by cuts in order to achieve mechanical uncoupling. However, this proposal also causes high production costs and moreover, leads to high susceptibility to breaking of the arrangement.